Function new_invocation 

pub async fn new_invocation<P, Z>(
    cell_id: &CellId,
    func: &str,
    payload: P,
    zome: Z,
) -> Result<ZomeCallInvocation, SerializedBytesError>
where
    P: Serialize + Debug,
    Z: Into<Zome> + Clone,

Helper to create a zome invocation for tests